Jökull

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Jökull - 01.12.1956, Qupperneq 5

Jökull - 01.12.1956, Qupperneq 5
Fig. 2. Stóralda view- ed from N. Photo S. Thorarinsson 14 Sept. 1955. probably formed by a glacier advance during the first centuries of the Subatlantic Time (Thorarinsson 1946, p. 260—261) Todtmann has, in my opinion rightly, identified this mor- aine in a thrust moraine (Stauchmoráne) found beneath recent moraine cover in front of SE Breidamerkurjökull (Todtmann 1936). In a paper 1952 Todtmann regards this thrust moraine as prehistoric. She mentions in the same paper that she has found the 1362-tephra on the moraine Stóralda in front of Svínafells- jökull, which would mean that this moraine also was prehistoric, ancl she says further about. Ivvíárjökull that “vielleicht ist auch der Kern der hohen Seitenmoránen von sehr hohem Alter” (1952, p. 407). As the age of these moraines and that of Stóralda is of great interest from a climate historic point of view, I found it necessary to try to fix their age more de- finitely by means of tephrochronology, and during a short stay in Öræfi in the autumn of 1955 I visited both Svínafellsjökull and Kvíár- jökull for a further study, the result of which I shall now relate. SVÍNAFELLSJ ÖKULI, AND SKAFTAFELLSJÖKULL When travelling along the road from the Svínafell farm in Öræfi towards the farm Skafta- fell and having travelled ab. 1.5 km over the sandur plain west of the river Svínafellsá, one has on the right a plain patch of grassland called Svínanes. Above this grassland rises a curved higli moraine ridge and in front of it there are some lower, í'lat concentric ridges. This moraine complex as a whole is called Stór- alda and I refer here to the innermost and highest ridge as Stóralda proper. Its relative height on the steep proximal side is 20 m, that of the less steep distal side 16 m. The max. absolute height of Stóralda proper is 115 m and its length ab. 0.5 km. The ridges iir front, at least six in number, are flat gravel ridges, 50— 80 m broad. These ridges are rather like the flat folds in front of the thrust moraine formed by the sudden advance of Eyjabakkajökull in 1890 (Thorarinsson 1938, fig. 2). Whether the ridges in front of Stóralda proper are also folded by a rapidly advancing glacier (cf. Helga- son 1935, p. 15) or possibly formed as “Scher- fláchen” moraines has to be decided definitely by more detailed studies. The Stóralda proper, however, gives the impression of being a thrust moraine (cf. Todtmann 1952, Hoppe 1953). Information on the oscillations of Skaftafells- jökull and Svínafellsjökull until Eythórsson started measurements of their frontal variations in 1932 has been collected by Bárdarson (1936, p. 2) and supplemented by Thorarinsson (1943, pp. 32—33). It seems likely, from information I have got in Öræfi, that these glaciers have 3

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Jökull

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